Run TypeScript Natively in Node.js

Node.js has introduced the ability to run TypeScript directly without the need for source maps, using a feature called 'experimental strip types' that removes TypeScript-specific syntax to allow execution.

TypeScript was chosen due to its growing popularity and demand, as well as its status as a widely adopted JavaScript superset, unlike CoffeeScript or Flow, which have seen decreasing usage.

Challenges include TypeScript's lack of a specification, which can lead to breaking changes with minor updates, and the need for interoperability with ESM modules, which was recently resolved.

Type stripping removes TypeScript-specific syntax from the code, leaving only JavaScript code which can be executed. This process avoids the need for source maps, maintaining code location consistency by replacing removed syntax with blank spaces.

Amaro is a custom wrapper around the SWC library, specifically for Node.js, enabling the experimental strip types feature to run TypeScript code without needing source maps.

Enums are not supported in the type stripping feature because they require code transformation that affects runtime, which goes against the goal of type stripping to avoid runtime code generation.

The 'experimental transform types' flag allows for the transformation of TypeScript features that require it, such as enums, but it remains experimental and is not recommended for production use.

Developers should use the TSConfig flags like 'erasable syntax only', 'verbatim module syntax', and 'rewrite relative import extensions' to ensure compatibility with Node.js type stripping.

While experimental, the integration is stable enough for use, and many companies have adopted it. It is recommended for projects that do not prioritize startup time.

The Node.js team holds regular meetings with the TypeScript team to ensure alignment and support for the integration, addressing potential issues and future updates collaboratively.